Gas charging valve for accumulator

Abstract

This invention relates to the art of pressure vessels and more particularly to a valve assembly for use in a pressure vessel of the type having a rigid container with a deformable bladder therein, dividing the container into two variable volume chambers, one adapted to receive gas under pressure and the other to receive liquid under pressure. The valve assembly which is screwed into a port in communication with the gas chamber includes a slidably mounted stem having a resilient valve member at one end normally urged to seat on the beveled inner end of an axial bore in the valve assembly in a first seating position of the valve member, and urged further into said beveled inner end when the bladder is charged with gas under pressure in a second seating position of the valve member. The inward movement of the valve member is limited by a stop carried by the stem. When the liquid chamber is charged, if the bladder should abut against the resilient valve member, no extrusion of the bladder would occur.

Having thus described my invention, what I claim as new and desire to secure by letters patent of the United States is: 
     
       1. A pressure vessel comprising a container of rigid material having two ports, both axially aligned with said container, one of said ports defining a gas port and the other a liquid port, a partition intervening between said ports to define a variable volume gas chamber and a variable volume liquid chamber in communication with said gas port and liquid port, respectively, means to close said liquid port, means to charge said gas chamber with gas under pressure, said charging means comprising a valve assembly mounted in the gas port, said valve assembly comprising a bore having an inner end defining a valve seat, a valve stem slidably mounted in said bore, said stem being of dimensions such as to provide clearance for gas flow through said bore, said stem having an inner end, a valve disc of deformable resilient material mounted on said inner end of said stem, resilient means reacting against said stem to urge the latter outwardly to retain the outer surface of said valve disc against said seat in a first seating position, and means rigid with said stem adapted to abut against said valve seat when said valve disc is moved outwardly to a second seating position as a result of gas pressure in said gas chamber, to limit the outward movement of said valve disc. 
     
     
       2. The combination set forth in claim 1 in which the inner end of said bore is beveled to define said valve seat, said bore being of larger diameter at its inner end, said valve disc is an annular bead having a periphery which engages said larger diameter inner end of said beveled valve seat in the first seating position of said valve disc. 
     
     
       3. The combination set forth in claim 1 in which the inner end of said bore is beveled to define said valve seat, said valve seat being of larger diameter at its inner end and of smaller diameter at its outer end, the inner end of said valve stem extends into the valve seat and has a cylindrical portion of diameter greater than said smaller diameter outer end portion of said beveled seat, said stem having a cylindrical portion adjacent its inner end, said valve disc is an annular bead secured to said cylindrical portion of said stem, said bead having a periphery engaging said larger diameter portion of said beveled seat in the first seating position of said valve disc, said cylindrical portion of said stem engaging the smaller diameter outer end portion of said beveled seat in a second position of said valve disc, said bead being deformed into the beveled portion of said bore in the second seating position of said valve disc. 
     
     
       4. The combination set forth in claim 1 in which said bore has a reduced diameter portion near its inner end defining a shoulder, said stem has an outer end having an abutment, a coil spring encompassing said stem and reacting against said abutment and said shoulder, normally urging said stem outwardly to move said valve disc to its first seating position. 
     
     
       5. The combination set forth in claim 1 in which said gas port comprises an additional bore having an inner end of reduced diameter defining an annular shoulder, said reduced diameter end of said bore being internally threaded, said valve assembly comprises a casing of rigid material having said first named bore extending axially therethrough, said valve assembly having a transversely extending hub with externally threaded cylindrical portions extending axially from both sides thereof, one of said cylindrical portions being screwed into the reduced diameter bore portion, said first named bore extending through said cylindrical portions of said hub. 
     
     
       6. The combination set forth in claim 5 in which said hub defines opposed surfaces, the surface of said hub adjacent the cylindrical portion screwed into the reduced diameter bore portion has an annular recess in which an O-ring is positioned, said O-ring being compressed against said annular shoulder when the cylindrical portion is tightened to define a seal.